Method of incorporating filling material in paper.



UNITED STATES PATEN OFFICE.

GEORGE W. MILES, OF'BELMONT, MASSACHUSETTS, ASSIGNQR T0 ROSS CHEMICAL comrm, or BOSTON, MASSACHUSETTS, A CORPORATION or MAINE.

METHOD OF TNCORPORATING FILLING MATERIAL IN PAPER.

No Drawing'.

To all whom it may concern:

Be it known that I, GEORGE W. MILES, a citizen of the United States, and resident of Belmont, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Methods of Incorporating Filling Material in Paper, of which the following is a specification.

My invention relates to the manufacture of filled paper and consists in a novel method of introducing filling or coating material, such as china clay, blanc-fixe, satin white, or any of the finely comminuted mineral fillers which are habitually incorportated in the paper, and also in the product which results from the practice of my new method.

Heretofore paper manufacturers have incorporated limited amounts of filler, such as china clay, with the pulp before it passes to the paperweb-making machine. By the practice heretofore prevailing the fiber will carry only'a limited amount of clay or other filler, the maximum proportion being about twenty-five per cent. by weight of the finished paper web. Where larger amounts of filler than could be incorporated with the pulp have been desired, such as for the production of paper for half tonework, the additional amount in processes at present in vogue must be applied to the surface of the paper web, whereas by my new process hepein to be described the paper as it comes from the web-forming machine carries a suflicient amount of filler to be suitable for half tone work.

I have discovered that-if an emulsion of wax or waxy material such as stearic acid is introduced into the beater with the fiber together with a filler such as china clay, the

effect of the wax is to carry into association with the fiber a much larger proportion of the filler than can otherwise be incorporated, with it. By way of preferred modification of this treatment, I also add a size, such as rosin size. Moreover, I prefer, and recommend the use of, an emulsion of paraflin wax for this purpose. Paraflin wax can be eniulsified by a process which I have described and claimed in my United States Patent,

No. 1,168,534, dated January 18, 1916. Briefly described, this emulsification process is as follows Take of paraflin Wax. ninety-five parts, and of commercially dry soda tallow soap (containing about 20% water) five parts, by

Specification of Letters Patent.

Patented June 5, i917.

Application filed March 11,1915. Serial No. 13,692.

weight. Make a paste with the soap in from four to five times its weight of water. Then melt the paraffin wax and stir the paste into it,heat-approximatelyto the boiling point of water and maintain -the heat, meanwhile stirring or beating until, by evaporation, the water is reduced to that critical proportion which efi'ectuates the emulsification of the wax. The emulsion thus formed is quite thick, and may with advantage be extended by'the addition of morewater.

The introduction of such a wax emulsion into the pulp has this effect: that proportions of sizesuch as rosin sizemuch larger than heretofore possible can be employed, without incurring the detriment of foaming and sliming at any stage of the paper manufacture. While the introduction and use of the wax emulsion alone will enable the manufacturer to incorporate with the fiber a larger proportion of filling materialsuch as china c1ay-than heretofore, the employment of a size such as rosin size, in association with the wax emulsion will enable him to carry even larger proportions of filler with the fiber, nd, with increase in the proportion of size (made practically possible by the presence of wax emulsion) the proportion of filler may be increased to any extent within practical limits.

For example: To 200 parts (by weight) 1 -and the manufacture of the paper web, is carried out in the usual way, the size being precipitated with alum or the like. The paper thus produced, on being compacted or calendered, presents an excellent surface for printing or for the reception of half ton :process prints.

By the above described process, filled a per can be produced which is suitable or manypurposes for which heretofore coating of the finished paper web has been necessary.

, I claim:

1. A method of incorporating filling ma- ;with a proportion of filler in excess of that I which in the absence of said emulsion will incorporate with the fiber.

terial in paper, which consists in mixing with the fiber before its final formation into a paper web an emulsion of waxy material with a proportion of filler in excess of that which in the absence of said emulsion will incorporate with the fiber.

2. A method of incorporating filling nsteriel in paper, which consists in mixing with the fiber before its final formation into a paper web an emulsion of] parsffinwsx 3. A methodof incorporating filling material in paper which consists of mifing- With the fiber in the heater an emulsion of ssegso pareifin wax with a proportion of filler in.

excess of that which in the absence of said emulsion will incorporese with the fiber.

Signed. by me at Boston, Massachusetts,

"this 5th day of March 1915.

onosen w MILES.

Witnesses:

ROBERT CUsHMAN, i (Enemies D. WOODBERRY. 

